A steel rod \(1 \mathrm{~m}\) long and \(15 \mathrm{~mm}\) diameter is held between rigid supports as shown in Fig. 13.40 The temperature of the rod is increased by \(40^{\circ} \mathrm{C}\). The coefficient of linear expansion for steel is \(12 \times 10^{-6}{ }^{\circ} \mathrm{C}\). Caclulate the stress developed in the rod. \(E_{s}=200 \mathrm{GPa}\).